Out-of-order frames with identical timestamps

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I am using Wireshark on a Windows 11 PC, capturing OP cyclic frames from a TwinCAT PLC program acting as the EtherCAT master. The network has only two devices, this Master and one additional slave. Wireshark is running on the same Windows 11 PC.

The issue is random frames logged out of order and with identical timestamps Here is a snippet from a log showing this. Notice frames 5616 through 5619:

----------------------------------------
Frame | Time     | Source
----------------------------------------
5609  | 2.793484 | 10GtekTransc_22:21:a3  <--Good: Transmitted from Master
5610  | 2.793493 | BeckhoffAuto_01:00:00  <--Good: Paired with frame 5609 returned to Master
5612  | 2.794567 | 10GtekTransc_22:21:a3  <--Good: Transmitted from Master
5613  | 2.794576 | BeckhoffAuto_01:00:00  <--Good: Paired with frame 5612 returned to Master
5614  | 2.795562 | 10GtekTransc_22:21:a3  <--Good: Transmitted from Master
5615  | 2.795570 | BeckhoffAuto_01:00:00  <--Good: Paired with frame 5614 returned to Master

5616  | 2.796880 | 10GtekTransc_22:21:a3  <--Issue: From Master, has same Timestamp as #5617
5617  | 2.796880 | 10GtekTransc_22:21:a3  <--Issue: From Master, has same Timestamp as #5616
5618  | 2.796891 | BeckhoffAuto_01:00:00  <--Issue: To Master, same Timestamp as #5619
5619  | 2.796891 | BeckhoffAuto_01:00:00  <--Issue: To Master, same Timestamp as #5618

5620  | 2.797946 | 10GtekTransc_22:21:a3  <--Good: Transmitted from Master
5621  | 2.797953 | BeckhoffAuto_01:00:00  <--Good: Paired with frame 5620 returned to Master

Frames 5616 and 5618 are a matching TX/RX pair. Frames 5617 and 5619 are also paired frames. All the frames have unique payloads, so the frames can be easily matched. This example is repeated throughout the log with these anomalies occurring ~0.91% of the time (about 3,808 times out of over 150,000 frames captured).

I have read some other posts here, but none specifically like this, especially with EtherCAT where frames can only be in specific orders and period timing.

What are possible explanations for these out-of-order frames and the identical timestamps?